Generally, automotive vehicles, whether automobiles, trucks or buses, have a relatively high degree of stability even in situations where they are struck from the side by another vehicle at a relatively high velocity. The stability and resistance to such struck vehicle turning over is due to such factors as the relatively heavy weight of the vehicle, its relatively low center of gravity as well as the relatively wide lateral wheel spacing. However, a very small percentage of such automotive vehicles involved in crashes do, nevertheless, turn or roll over or otherwise severely change their attitude from what would be considered normal.
It has, for many years, been accepted practice to, in automotive vehicles, provide a fuel tank from where a fuel pump would draw fuel and in turn supply such fuel to, for example, a fuel metering device on a remotely situated engine.
Often times such fuel metering devices take the form of a carburetor with an associated fuel bowl including a float-valve assembly therein. In many such arrangements there is a vent passage which in effect serves to complete communication as between the interior of the fuel bowl (above the fuel contained therein) and a source of ambient atmosphere as, for example, some point or area within and downstream of the engine intake air cleaner.
If the very small percentage of such automotive vehicles which do turn over, roll-over or otherwise severely change their attitude it has been found that a further small percentage thereof have had fuel spill out of the vent tube or passage (or other passages communicating with the engine intake system) and flow over the engine and associated structure. In such instances, after investigations, it has been determined that because of the particular physical attitude or position assumed by the struck vehicle the fuel tank may actually assume an elevation above that of the carburetor fuel bowl. Because of such a change in relative elevations the liquid pressure head of the fuel within the fuel tank becomes sufficient to cause fuel to flow through the fuel pump (even though the fuel pump may not be operating) and into the carburetor fuel bowl from where such fuel, as previously indicated, can spill over onto the engine and associated structure. Such spilled fuel can, in turn, under circumstances giving rise to such a condition, ignite with the resulting flames being capable of starting the entire vehicle to burn.
Even though the occurrence of such crash situations leading to such fuel-caused fires is rare, nevertheless, the invention as herein disclosed and described is directed to the solution of such as well as other attendent and related problems.